This invention relates in general to three wheel tricycles powered both by leg powered peddles and arm powered movable handlebars.
A wide variety of propulsion systems have been developed for bicycles, tricycles, etc. Commonly, such cycles have a rotating sprocket connected to pedals that revolve around the sprocket axis, with the sprocket carrying a chain driving a sprocket connected to the rear wheel. The front wheel is mounted on a stem and is turned by a pair of outwardly extending handlebars. Whether the rider is positioned in an upright or recumbent position, the cycle is relatively easy to steer and propel. The arms are used solely for steering and are not involved in propelling the cycle.
A number of different drive systems have been devised to gain additional propelling energy from the arms. Typical of these are the xe2x80x9crowingxe2x80x9d type systems described by Young in U.S. Pat. No. 5,272,928, McCahon in U.S. Pat. No. 5,653,663 and Keskitalo in U.S. Pat. No. 5,690,346. Each of these recumbent cycles uses a xe2x80x9crowingxe2x80x9d motion in which handles and pedals are alternately pushed back in forth in a generally straight line. Handles or a handle assembly must be rotated or pivoted while being moved back and forth. With these complex mechanisms and straight line motion, maintaining balance and smoothly steering while providing maximum power is quite difficult.
Braun in U.S. Pat. No. 4,541,647 combines pedals on a sprocket for rotation by the legs and two closely spaced handles alternately pushed and pulled forward and back. One handle is pushed forward while the other is pulled back, creating unbalanced forces which will make steering the cycle by tilting the handle assembly very difficult.
Sommer et al. in U.S. Pat. No. 5,328,195 describe a basically conventional bicycle having a pedal sprocket connected to a drive sprocket at the rear wheel with handlebars that can be lifted and lowered as a unit. The handlebar motion pulls a cable wrapped around a pulley secured to the drive sprocket to provide added rotational force during the lifting phase of handlebar movement. Lifting handlebars generate considerably less force that will a pulling motion back toward the rider and a cable and pulley arrangement is much less positive than a chain and sprocket.
Thus, there is a continuing need for a cycle, particularly for off-road riding, that is simple is structure and avoids unreliable complexity, is low to the ground for increased stability and lower wind resistance, provides for increase power generation by both a rider""s arms and legs and avoids unbalanced forces on the steering mechanism to provide easy and accurate steering while providing maximum arm propulsive forces.
The above-noted problems, and others, are overcome by the dual power tricycle of this invention, which basically comprises a frame, a rider""s seat mounted on the frame, three wheels mounted on the frame, with two wheels forward and one aft of the seat or, alternatively, one forward and two aft of the seat, a foot power assembly connected between foot pedals operable by a rider""s feet and at least one of the wheels for rotating the wheels in response to foot pedal rotation, two hand levers operable by a rider""s hands for moving forward and aft, a hand power assembly connected between said hand levers and at least one of the wheels for further rotating said wheels in response to forward and aft movement of said hand levers, steering means for steering forward wheel(s) in response to sideways movement of said hand levers and brake operating means mounted on said hand levers and connected to wheel rotation braking means at least some of said wheels.
While the frame may be constructed of any suitable material and components, a welded tubular metal frame and/or a tubular fiber reinforced resin frame is preferred. Any suitable seat may be used. Preferably, since the rider sits in a semi-recumbent position with his or her legs extending forward, the seat has a back.
The foot poser assembly comprised a pair of conventional foot pedals forward of the seat, directly driving a first sprocket connected via a chain and conventional gearbox(es) to the rear wheel(s). Preferably, a first conventional gear changing mechanism is provided adjacent to the pedals with a gear changing lever for the first gear changer on one hand lever. A second conventional gear box is positioned generally below the seat, with a second gear changing lever for the rear gear box mounted on the second hand lever. Regular bicycle chains run from the first gear box to the second gear box and then to the wheel. Idler gears are provided as desired to direct the chain between these components and to adjust chain tension.
The hand power assembly comprises the two hand levers mounted so as to pivot forward and aft about a pivot point at the lower ends of the levers. A standard bicycle chain is secured to a crosspiece connecting the two hand levers, wraps around a ratchet sprocket attached coaxially with the first sprocket and pedals, then to a stiff spring fastened to the frame. When the handles are not moved forward and aft (or are moved slowly) the ratchet sprocket free wheels. When the handles are moved sufficiently rapidly to cause the rim speed of the ratchet sprocket to exceed the rim of the first sprocket, the ratchet will lock and the force rotating the ratchet sprocket is transmitted to the drive chain assembly, increasing vehicle speed. Generally, the ratchet sprocket will have a considerably smaller diameter than the first sprocket, since the foot pedaling speed is likely to be greater than the hand lever motion.
The lower ends of the hand levers are mounted on the crosspiece so as to be pivotable to either side. A bracket on the crosspiece pivots sideways with the hand levers. A cable connected to sides of the bracket is connected to a tie rod adjacent to the front wheel(s) axis, so that sideways pivoting of the hand levers will cause rotation of the front wheel(s) about a generally vertical axis, steering the vehicle.
Each of the three wheels is preferably mounted on a shock absorbing assembly, to reduce bumps and vibration when the vehicle is ridden along a rough surface.
Conventional caliper brakes are mounted to engage the front wheel(s) via conventional handlebar mounted levers and cables. A disk brake is mounted along a side of the rear wheel(s) and is actuated by levers.